Semiconductor integrated circuit device, and adjustment method of semiconductor integrated circuit device

ABSTRACT

It is intended to provide a semiconductor integrated circuit device and adjustment method of the same semiconductor integrated circuit device, capable of adjusting an analog signal outputted from an incorporated analog signal generating section without outputting it outside as an analog value. An analog signal AOUT is outputted from an analog signal generating section  3  in which an adjustment signal AD is inputted. The analog signal AOUT is inputted to a judgment section  1 , in which it is compared and judged with a predetermined value and then a judgment signal JG is outputted. The judgment signal JG acts on a predetermined signal storing section  4  as an internal signal and the adjustment signal AD is fetched into the predetermined signal storing section  4 . Further, the judgment signal JG is outputted as digital signal through an external terminal T 2  and an external tester device acquires the adjustment signal and stores the acquired adjustment signal in the predetermined signal storing section  4 . Consequently, the analog signal can be adjusted as analog value without being outputted outside and an adjustment test can be carried out with a simple tester device and according to a simple test method accurately and rapidly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromeach of the prior Japanese Patent Application No. 2002-248134 filed onAug. 28, 2002 and No. 2003-192151 filed on Jul. 4, 2003 the entirecontents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to adjustment of analog signal outputtedfrom an analog signal generating section of an internal power sourcecircuit or the like incorporated in a semiconductor integrated circuitdevice, and more particularly to a semiconductor integrated circuitdevice in which interface for input-output signals is achieved bydigital signal and adjustment method of the semiconductor integratedcircuit device.

2. Description of Related Art

FIG. 17 shows an internal power source circuit 300 incorporated in asemiconductor integrated circuit device, a fuse circuit 400 foradjusting the voltage of an internal power source voltage VII, and adecoding circuit 600 as circuit examples based on conventionaltechnology. The internal power source circuit 300 is constituted of anon-inverting amplification circuit employing an operational amplifiercircuit. If a gate voltage of a PMOS transistor MP1 is controlled by anoutput signal of the operational amplifier circuit, a reference voltageVREF inputted from a reference terminal REF, which is an inverting inputterminal, is subjected to non-inverting amplification so as to generatethe internal power source voltage VII. An amplification rate at thistime is determined by selecting resistance elements R, R0-R3 connectedto a path from the output terminal of the internal power source voltageVII to the non-inverting input terminal VAF of the operational amplifiercircuit. This selection is performed by supplying electricity to any oneof transfer gates S0-S3 connected between the respective resistanceelements R, R0-R3.

This selection is carried out by the decoding circuit 600. The decodingcircuit 600 decodes predetermined signals FS<0>, <1> stored in the fusecircuit 400 and selects any one of decoding signals D<0>-D<3>. Two-phasesignals of in-phase and anti-phase for each of the predetermined signalsFS<0>, <1> are generated and logical add operation is executed bycombining the respective signals so as to obtain the decoding signalD<0>-<3>.

The fuse circuit 400 is constituted of a resistance element and a fuseelement and stores predetermined signals FS<0>,<1> for outputting apredetermined internal power source voltage VII. The fuse element is notcut out when a low level signal is stored and the fuse element is cutout when a high level signal is stored. In the semiconductor integratedcircuit, individual device characteristics vary because ofcharacteristic variation due to manufacturing reason and generally, thereference voltage VREF inputted to the reference terminal REF alsovaries. The predetermined signals FS<0>, <1> are signals for correctingthis variation so as to output the predetermined internal power sourcevoltage VII and is set up for each internal power source circuit 300.This setting work is called trimming work and carried out according to atest flow shown in FIG. 18.

In the test flow of FIG. 18, the internal power source voltage VII ismeasured with a tester device, which is an external device of thesemiconductor integrated circuit. Because the fuse element is not cutout at this stage, the predetermined signals FS<0>, <1> are low levelsignals. A transfer gate S0 is selected in the internal power sourcecircuit 300 so as to set up a minimum amplification rate. How theamplification rate of the internal power source circuit 300 should bechanged can be calculated preliminarily based on a measured voltagevalue of the internal power source voltage VII. That is, a fuse elementwhich should be cut out is predetermined depending on a differencebetween an initially measured voltage value of the internal power sourcevoltage VII and the predetermined value. FIG. 18 shows a test flow forbreaking a fuse element depending on the measured internal power sourcevoltage VII.

If the initially measured internal power source voltage VII is a voltagevalue VIIX lower than a range adjustable by selecting the amplificationrate (VII<VIIX), the semiconductor integrated circuit is a defectiveproduct. If it is over the predetermined voltage value VIIZ (VII≧VIIZ),the fuse element does not have to be cut out. If respective transfergates S1, S2 are selected, the initially measured voltage values VII,which is to be set as the predetermined voltage value VIIZ, are assumedto be VII1, VII2. Consequently, if the initially measured voltage valueVII is VIIX, VII2, VII1, VIIZ, a fuse element which should be cut outcorresponding thereto is automatically determined.

According to a conventional technology, if the internal power sourcevoltage VII in the semiconductor integrated circuit incorporating theinternal power source circuit 300 is trimmed, the internal power sourcevoltage VII needs to be measured according to a trimming test flow.Therefore, analog data which enables measurement of analog voltage needsto be used for the trimming test. If other analog circuit than theinternal power source circuit 300 is loaded, the analog signal foradjustment needs to be also measured.

On the other hand, with intensification and miniaturization ofsemiconductor integrated circuit technology in recent years, thesemiconductor integrated circuit in digital field, which is representedby system LSI, has been loaded with an analog circuit block containinganalog function such as an internal power source circuit.

For the reason, the semiconductor integrated circuit, which employsdigital signal as an input-output interface to an external terminal,needs to be provided with a special measuring terminal (analog terminal)for adjusting the analog signal such as the internal power sourcevoltage, which is a problem to be solved.

More specifically, the analog circuit block, which is provided in thesemiconductor integrated circuit, is disposed at an arbitrary positioncorresponding to semiconductor integrated circuit design. Where theanalog terminal should be disposed differs depending on the design. Awiring path, wiring length, wiring load and the like from the analogcircuit block to the analog terminal differ depending on thesemiconductor integrated circuit design. In order to output an analogsignal to the analog terminal at a high precision, a sufficient careneeds to be taken to changes or the like of the analog value due tomixture of noise by digital signals from peripheral circuits block oradjacent wirings and wiring load on a wiring path for each design.Consequently, a great burden is applied to its design aspect in order toprovide with a special analog terminal necessary for adjustment of theanalog signal, which is a problem to be solved.

Further, with a test on the digital signal inputted/outputted into/fromthe digital terminal, an analog signal outputted from the analogterminal needs to be measured. That is, both digital test and analogtest need to be carried out at the same time. Thus, it is necessary toprepare a tester device having both digital testing function and analogtesting function. Consequently, the tester device becomes complicatedand expensive, so that testing time automatically increases. Through-putfrom the test worsens and cost necessary for the test increases, whichare problems which should be solved.

Further, the digital test and analog test need to be carried outindependently and when the analog test is performed, the digitalfunction needs to be kept in a predetermined state. For the reason, aninfluence upon the analog signal by the operation of the digitalfunction cannot be tested, which is a problem to be solved.

SUMMARY OF THE INVENTION

The present invention has been made to solve at least one of theafore-mentioned problems that the prior art has had. It is an object ofthe present invention to provide a semiconductor integrated circuitdevice and an adjustment method of a semiconductor integrated circuitdevice capable of adjusting an analog signal without outputting theanalog signal to the external in a form of an analog value wherein ananalog signal to be adjusted is outputted from an analog signalgenerating section such as an internal power source circuit or the likebuilt in the semiconductor integrated circuit device.

To achieve the object, according to one aspect of the present invention,there is provided a semiconductor integrated circuit device comprising:an analog signal generating section for outputting an analog signal; anda predetermined signal storing section for storing at least onepredetermined signal that is supplied to the analog signal generatingsection and sets the analog signal to a predetermined value, whereindigital signals are used for input/output interface to externalterminals, for adjusting the analog signal, the semiconductor integratedcircuit device further comprises a judgment section for outputting atleast one judgment signal that corresponds to a comparison result of theanalog signal corresponding to at least one adjustment signal and thepredetermined value generated based on power source voltage, for eachadjustment signal supplied to the analog signal generating section inaccordance with a test signal, and in case the judgment signal judgesthat the analog signal has the predetermined value, the adjustmentsignal corresponding to the as-judged analog signal is stored in thepredetermined signal storing section as the predetermined signal.

In the semiconductor integrated circuit device directed to the oneaspect of the present invention, when an analog signal is adjusted forthe analog signal generating section build in a semiconductor integratedcircuit device wherein digital signals are used for input/outputinterface to external terminals, at least one adjustment signal issupplied for generating an analog signal. The judgment section comparesthe generated analog signal with the predetermined value generated basedon power source and output the comparison result in a form of at leastone judgment signal. The predetermined signal storing section stores anadjustment signal that adjusts an analog value to a predetermined valuein accordance with at least one judgment signal in a form of apredetermined signal.

Furthermore, there is provided an adjustment method of the semiconductorintegrate circuit device, directed to the one aspect of the presentinvention, there is provided an adjustment method of a semiconductorintegrated circuit device that generates an analog signal having apredetermined value based on at least one predetermined signal storedand uses digital signals for input/output interface to externalterminals, for adjusting the analog signal, the adjustment methodcomprising the steps of: a signal generating step for generating theanalog signal that corresponds to at least one adjustment signal; ajudgment step for judging a comparison result of the analog signalgenerated and the predetermined value generated based on power sourcevoltage, the judgment step being executed inside the semiconductorintegrated circuit device; and a storing step for storing the adjustmentsignal as the predetermined signal in case the analog signal is judgedas having the predetermined value through the judgment step.

In the adjustment method of the semiconductor integrated circuit devicedirected to the one aspect of the present invention, when an analogsignal is adjusted for the analog signal generating section build in asemiconductor integrated circuit device wherein digital signals are usedfor input/output interface to external terminals, an analog signalcorresponding to at least one adjustment signal is generated in thesignal generating step, and in the judgment step, an analog signalgenerated and the predetermined value generated based on power sourcevoltage are compared inside the semiconductor integrated circuit device.In the storing step, at least one adjustment signal is stored as atleast one predetermined signal in case the analog signal is judged ashaving the predetermined value.

Since the judgment section or the judgment step is provided, an analogsignal outputted for each adjustment signal and the predetermined valuecan be compared. Thereby, judgment of analog signal can be executedinside the semiconductor integrated circuit device.

That is, it is not necessary to output an analog signal to the externalterminal of the semiconductor integrated circuit device. Furthermore, itis not necessary to arrange an output dedicated external terminal for ananalog signal and wiring for an analog signal to the output dedicatedexternal. Thereby, consideration for analog wiring is not necessitatedand this contributes to simplification of design process of ansemiconductor integrated circuit device.

Furthermore, since an analog signal is not outputted from the externalterminal, a test for an analog signal is not required. That is, theremay be arranged a tester device having digital function for adigital-interface-type external terminal. It is not necessary to providea complicated tester device that has both digital function and analogfunction. Furthermore, the inventive semiconductor integrated circuitdevice does not require system to switch test condition between digitalfunction and analog function, whereby overhead of test time due toswitching operation. Reduce of test cost thus can be realized.

It should be noted that the predetermined value herein is a value for acomparison judgment of an analog signal as well as an analog value. Thepredetermined value can be generated based on power source voltage thatis supplied to the semiconductor integrated circuit device at the timeof adjustment test. Once power source voltage is set as thepredetermined voltage value for adjustment test, it is not necessary toinput a predetermined analog value from an external terminal aspredetermined value. A predetermined value can be generated byappropriately lowering/dividing power source voltage or appropriatelycombining those resultant voltages.

Furthermore, it is preferable that the predetermined value is apredetermined analog value region between a first comparison referencevalue and a second comparison reference value and the judgment signaljudges which analog value region sectioned by two or more comparisonreference values including the first and the second comparison referencevalues the analog signal exists in. Thereby, fluctuation of the analogsignal from the predetermined value can be grasped and depending onjudgment result, at least one adjustment signal can be fluctuated tomake the analog signal approximate the predetermined value immediately.

It is preferable that the judgment section includes a plurality ofcomparing sections for comparing the analog signal with each of the twoor more comparison reference values, and an encoding section foroutputting encoding signals in a manner of receiving output signals fromthe plurality of comparing sections and discriminating the analog valueregion where the analog signal exists. As encoding signals, the encodingsection may output digital signals that have a minimum essential numberof bits being enough to discriminate analog value regions.

Furthermore, according to another aspect of the present invention, thereis provided a semiconductor integrated circuit device comprising: ananalog signal generating section for outputting an analog signal; and apredetermined signal storing section for storing at least onepredetermined signal that is supplied to the analog signal generatingsection and sets the analog signal to a predetermined value, whereindigital signals are used for input/output interface to externalterminals, and the semiconductor integrated circuit device furthercomprises virtual load section for varying load against the analogsignal in response to a load setting signal to be supplied. Stillfurther, there is provided an adjustment method of the semiconductorintegrate circuit device, directed to the another aspect of the presentinvention, there is provided an adjustment method of a semiconductorintegrated circuit device that generates an analog signal having apredetermined value based on at least one predetermined signal storedand uses digital signals for input/output interface to externalterminals, the adjustment method adjusting the analog signal through avirtual load step for varying load against the analog signal inaccordance with a load setting signal. Since there is provided thevirtual load section or the virtual load step, virtual load can beconnected appropriately. Various operation states inside a semiconductorintegrated circuit device such as digital function and other analogfunction can be reproduced like a simulation. This adjustment method maybe applied to a test for analog signal adjustment so that analog signaladjustment can be conducted under load condition close to actualoperation.

The above and further objects and novel features of the invention willmore fully appear from the following detailed description when the sameis read in connection with the accompanying drawings. It is to beexpressly understood, however, that the drawings are for the purpose ofillustration only and are not intended as a definition of the limits ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a first principle diagram of the present invention;

FIG. 2 is a second principle diagram of the present invention;

FIG. 3 is a circuit block diagram of a first embodiment;

FIG. 4 is a circuit diagram of a specific example directed to the firstembodiment;

FIG. 5 shows operational waveform of the specific example directed tothe first embodiment;

FIG. 6 is a trimming test flow of the first embodiment;

FIG. 7 is a circuit diagram of a variant of a judgment section;

FIG. 8 is a circuit block diagram of a second embodiment;

FIG. 9 is a circuit diagram of a specific example directed to the secondembodiment;

FIG. 10 shows operational waveform of the specific example directed tothe second embodiment;

FIG. 11 is a trimming test flow of the second embodiment;

FIG. 12 is a circuit block diagram of a third embodiment;

FIG. 13 is a circuit diagram of a specific example directed to the thirdembodiment;

FIG. 14 is a circuit diagram of a first specific example directed to afourth embodiment;

FIG. 15 is a circuit diagram of a second specific example directed tothe fourth embodiment;

FIG. 16 shows operational waveform obtained incase multiple judgment ismade;

FIG. 17 is a circuit diagram of prior art; and

FIG. 18 is a conventional trimming test flow.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a first principle diagram of the present invention. Ananalog signal AOUT is outputted from an analog signal generating section3 in which an adjustment signal AD is inputted. If the adjustment signalAD is digital signal, the analog signal AOUT is outputted from thedigital signal by the analog signal generating section 3 andinput-output signal is subjected to D/A conversion by the analog signalgenerating section 3. If the adjustment signal AD is digital signal, theadjustment signal AD may be inputted from an external terminal T1.Contrary to this, an analog signal AOUT is a signal used in thesemiconductor integrated circuit device and never outputted as an analogsignal from an external terminal.

The analog signal AOUT is inputted to a judgment section 1 and comparedwith a predetermined value for judgment. The predetermined value is areference value for comparison and judgment and needs to be kept at apredetermined fixed value. A judgment section 1 generates a judgmentsignal based on the power source voltage VDD supplied to an externalterminal T3. In a test operation including adjustment of the analogsignal, the power source voltage VDD supplied to the semiconductorintegrated circuit device can be kept at a predetermined voltage valuewhen it is supplied. Therefore, the predetermined value can be generatedbased on the power source voltage VDD supplied to the external terminalT3. The power source voltage VDD needs to be always supplied so as tooperate the semiconductor integrated circuit device. By using the powersource voltage VDD, the predetermined value can be generated withoutsupplying any analog signal from the external terminal.

The judgment signal JG is outputted from the judgment section 1. Thisjudgment signal JG may be made to act on a predetermined signal storingsection 4 as an internal signal of the semiconductor integrated circuitdevice and further, may be outputted through an external terminal T2. Ifthe judgment signal JG is made to act on the predetermined signalstoring section 4, the adjustment signal AD is fetched into thepredetermined signal storing section 4 based on the judgment signal JG.If the judgment signal is outputted from the external terminal T2, thejudgment signal JG is digital signal. An outputted judgment signal JG isinputted to a control section (not shown) outside such as a testerdevice. The external control section acquires the adjustment signal ADat this time based on the judgment signal JG and terminates theadjustment test operation at the same time. Then, the external controlsection stores an acquired adjustment signal as a predetermined signalprior to or after the termination of the adjustment test operation. If adigital signal JG is outputted corresponding to the analog signal AOUTto be inputted to the judgment section 1, the input-output signal issubjected to A/D conversion at the judgment section 1.

The predetermined signal storing section 4 can be constituted ofelectrically rewritable memory elements regardless of volatile ornonvolatile, by a circuit structure having data holding function such asa register, flip-flop. Further, a fuse element, a 1-time ROM or the likewhich enables write of only a single time may be used. The fuse elementmay be cut out electrically in addition to cutting with laser radiationor the like. Here, the electric processing may be controlled within thesemiconductor integrated circuit device or by any external controlsection.

FIG. 2 shows a second principle diagram of the present invention. Theanalog signal generating section 3 outputs an analog signal AOUTcorresponding to the adjustment signal AD. A virtual load section 2 isconnected to the analog signal AOUT. The virtual load section 2 canchange a load connected to the analog signal AOUT under a control by theload setting signal LDS. If the load setting signal LDS is set upappropriately, a similar load to a load applied to the analog signal ADcan be connected falsely under each operation state of the semiconductorintegrated circuit device. If the load setting signal LDS is set up whenthe analog signal AOUT is adjusted according to the adjustment signalAD, the analog signal AOUT can be judged by connecting a similar load toactual operation without actuating the semiconductor integrated circuitdevice.

Here, it may be so constructed that the adjustment signal AD and theload setting signal LDS is generated within the semiconductor integratedcircuit device or inputted from outside through the external terminalT1, T4. If the adjustment signal AD and the load setting signal LDS areinputted from outside through the external terminal T1, T4, thesesignals are digital signals.

Hereinafter, the first to fourth embodiments of the semiconductorintegrated circuit device and adjustment method of the semiconductorintegrated circuit device of the present invention will be described indetail with reference to drawings of FIGS. 3-16. The first to fourthembodiments adopt such a circuit structure in which an internal powersource circuit 31 is provided as the analog signal generating section 3and the internal power source voltage VII is outputted as the analogsignal AOUT.

FIG. 3 shows a circuit block diagram of the first embodiment foradjustment of the internal power source voltage VII. An adjustmentsignal EAD<m:0> to be inputted from an external terminal T11 is inputtedto one input terminal of a multiplexer 51. A predetermined signalFS<m:0>, which is to be stored in a fuse circuit (or memory circuit) 41,is inputted to the other input terminal of the multiplexer 51. Themultiplexer 51 is controlled by a test signal TS inputted to theexternal terminal T15. In adjustment test for the internal power sourcevoltage VII, the adjustment signal EAD<m:0> is selected. In a normalstate after the adjustment signal is stored in the fuse circuit (ormemory circuit) 41 after the adjustment test is completed, thepredetermined signal FS<m:0> is selected. The selected signal EAD<m:0>or FS<m:0> is decoded by a decoding circuit 61. A decoding signal D<n:0>outputted from the decoding circuit 61 is inputted to the internal powersource circuit 31.

The internal power source voltage VII outputted from the internal powersource circuit 31 is inputted to a comparing section 12 in the judgmentsection 11. Further, the power source voltage VDD supplied to theexternal terminal T13 is inputted to the comparing section 12. Thecomparing section 12 sets up a predetermined value based on the powersource voltage VDD. A comparison result signal J from the comparingsection 12 is inputted to the encoding section 13. Then, the encodingsection 13 judges a comparison result and the judgment signal JG isoutputted.

For storage of the adjustment signal EAD<m:0> to the fuse circuit (ormemory circuit) 41, a case where it is controlled within thesemiconductor integrated circuit device and a case where it iscontrolled by an external control device (not shown) such as a testerdevice can be considered. If it is controlled internally, the judgmentsignal JG is inputted to the fuse circuit (or memory circuit) 41 as acontrol signal and by blowing of the fuse element based on the judgmentsignal JG or writing operation into the memory element, the adjustmentsignal EAD<m:0> is fetched in. If it is controlled from outside, thejudgment signal JG is digital signal and outputted from the externalterminal T12. By blowing of the fuse element from outside or writingoperation into the memory element based on the outputted judgment signalJG, the adjustment signal EAD<m:0> is stored. When it is also controlledinternally, it is permissible to output the judgment signal JG from theexternal terminal T12 as digital signal. In this case, it is possible tonotify of completion of the adjustment test operation with the judgmentsignal JG and stop supply of the test signal TS and adjustment signalEAD<m:0>.

If the test signal TS inputted from the external terminal T15 isactivated, the adjustment signal EAD<m:0> is inputted from the externalterminal T11 every predetermined cycle. The inputted adjustment signalEAD<m:0> is decoded to a decoding signal D<n:0> by the decoding circuit61 through the multiplexer 51 and inputted to the internal power sourcecircuit 31. The internal power source circuit 31 outputs the internalpower source voltage VII corresponding to the decoding signal D<n:0>.The outputted internal power source voltage VII is inputted to thecomparing section 12 in the judgment section 11 and compared with apredetermined value generated based on the power source voltage VDD. Thecomparison result signal J is inputted to the encoding section 13. Theencoding section 13 judges a comparison result so as to output thejudgment signal JG. If it is judged that the judgment signal JG does notcoincide with the predetermined value of the internal power sourcevoltage VII, the adjustment signal EAD<m:0> is updated after apredetermined cycle and inputted and then, the comparison judgmentoperation is repeated. If it is judged that the judgment signal JGcoincides with the predetermined value of the internal power sourcevoltage VII, the adjustment signal EAD<m:0> produced as a result of thejudgment on that coincidence is stored in the fuse circuit (or memorycircuit) 41 by internal control or external control depending on settingof the semiconductor integrated circuit device.

FIG. 4 shows a specific circuit diagram of the first embodiment. ThisFigure indicates that 2-bit signal (m=1) is inputted from the externalterminals T11A, T11B as the adjustment signal EAD <1:0>. The fusecircuit 41A stores the predetermined signal FS<1:0> at a connectionpoint between a resistance element connected to the power source voltageand the fuse element F<1:0> connected to the ground voltage. If the fuseelement F<1:0> is not cut out, a low level signal is stored and if it iscut out, a high level signal is stored.

The multiplexer 51A selects either one of the adjustment signal EAD<1:0>and the predetermined signal FS<1:0>. Transfer gates SE0, SE1 and SF0,SF1 are provided between each signal path and the output terminal. Eachtransfer gate is supplied with electricity and controlled by a testsignal TS inputted from the external terminal T15A. The transfer gatesSE0, SE1 and the transfer gates SF0, SF1 are controlled exclusively fromeach other because the connecting relations of the transfer gates SE0,SE1 and the transfer gates SF0, SF1 are reverse to each other. Thetransfer gates SE0, SE1 are supplied with electricity by a low levelsignal of the test signal TS so that the predetermined signal EAD <1:0>is selected. The transfer gate SF0, SF1 are supplied with electricity bya high level signal of the test signal TS so that the predeterminedsignal FS<1:0> is selected. The adjustment test operation for theinternal power source voltage VII is carried out by a low level signalof the test signal TS.

The two-bit signals selected by the multiplexer 51A are inputted to thedecoding circuit 61A. After that signals are inputted, signals of thein-phase and anti-phase are generated for each bit. Four types ofdecoding are carried out corresponding to combinations of the respectivesignals. That is, if the adjustment signals EAD<1:0> are taken as anexample, decoding signals D<0>-D<3> are selected successively to(EAD<1>, EAD<0>)=(0, 0), (0, 1), (1, 0), (1, 1) by NOR-gate NOR0-NOR3 soas to produce high level signals.

The internal power source circuit 31A outputs the internal power sourcevoltage VII from a connection point between the PMOS transistor MP1 andthe resistance element array of R, R0-R3. The gate terminal of the PMOStransistor MP1 is controlled by an operation amplifier. The referencevoltage VREF is inputted to a reverse-input terminal of the operationamplifier from the reference terminal REF. A feedback loop isconstructed between the non-inverting input terminal and the outputterminal of the internal power source voltage VII. A fed-back feedbackvoltage VAF is inputted to the non-inverting input terminal. Thetransfer gates S0-S3 for connecting between each connection point of theresistance element array of R, R0-R3 and the non-inverting inputterminal are selected corresponding to the decoding signals D<0>-D<3> soas to form a feedback loop. The internal power source circuit 31A is anon-inverting amplification circuit having a predetermined amplificationrate which is determined by a feedback position in the resistanceelement array of R, R0-R3.

In this feedback loop, depending on switching of the decoding signalsD<0>-D<3> accompanied by switching of the adjustment signals EAD<1:0>,each of the transfer gates S0-S3 is turned ON successively. The feedbackpositions in the resistance element array of R, R0-R3 are shifted to lowvoltage side successively so as to increase the amplification rate. Theinternal power source voltage VII is raised successively so as to obtainan output voltage value.

The internal power source voltage VII is inputted to the comparingsection 12A. The comparing section 12A contains two comparators C0, C1.Reference voltages VII0, VII1 of the respective comparators C0, C1 areobtained by dividing the power source voltage VDD inputted from theexternal terminal T13A with resistance elements RC0-RC2. Here, a voltagevalue region between the reference voltage VII0 and VII1 is apredetermined value. If the internal power source voltage VII isinputted to each of the comparators C0, C1, comparison of voltage withthe predetermined value is carried out. If the internal power sourcevoltage VII is in a lower voltage value region than VII0 and if in ahigher voltage value region than VII1, the comparison signals J<0>, J<1>outputted from each of the comparators C0, C1 are of the in-phase. Ifthe comparison signals are in a voltage value region between thereference voltages VII0 and VII1, the comparison signals J<0>, J<1> areof anti-phase.

The encoding section 13A, which encodes the comparison signals J<0>,J<1> so as to output the judgment signal JG, inverts the comparisonsignal J<0> logically and acquires NOR logic between the comparisonsignal J<1> and J(C). If the internal power source voltage exists in avoltage value region between the reference voltages VII0 and VII1 asdescribed above, the comparison signals J<0>, J<1> are of the anti-phaseand input signals to the NOR gate become low level. Therefore, in thiscase, a high level signal is outputted as the judgment signal JG and itis determined that the internal power source voltage VII is apredetermined value. Because the judgment signal JG outputted from theencoding section 13A is digital signal, it can be outputted from aexternal terminal T12A. The judgment section is constituted of thecomparing section 12A and the encoding section 13A.

FIG. 5 shows an operation waveform in a specific example of the firstembodiment. If the test signal TS is inverted to low level, theadjustment test on the internal power source voltage VII is started.With this state, the adjustment signals EAD <1:0> are incrementedsuccessively from a logical level of (0, 0). Because the adjustmentsignals EAD<1:0> are selected by the multiplexer 51A corresponding tothe test signal TS, each of the decoding signals D<0>-D<3> is selectedsuccessively to produce high level signal. The amplification rate of theinternal power source circuit 31A is increased corresponding toselection of the decoding signals D<0>-D<3>. Therefore, the internalpower source voltage VII is increased successively.

Because the internal power source voltage VII is smaller than thereference voltage VII0 of the comparing section 12A when the decodingsignal D<0> and D<1> is selected, the comparison signals J<0>, J<1> areof high level. Because the internal power source voltage VII is largerthan the reference voltage VII1 of the comparing section 12A when thedecoding signal D<3> is selected, the comparison signals J<0>, J<1> areof low level. In either case, one input terminal of the NOR gate of theencoding section 13A becomes high level. Therefore, the judgment signalJG keeps low level.

When the decoding signal D<2> is selected, the internal power sourcevoltage VII is located between the reference voltages VII0 and VII1 ofthe comparing section 12A. Thus, the comparison signal J<0> is of highlevel while the J<1> is low level. The input terminals of the NOR gateof the encoding section 13A become low level. Therefore, the judgmentsignal JG becomes high level.

The adjustment signals EAD<1:0> at this time are memorized in anexternal control section by the judgment signal JG outputted from theexternal terminal T12A. After the test signal TS is inverted to highlevel and the adjustment test is terminated, a predetermined fuseelement in a fuse circuit 41A is cut out. More specifically, the fuseelement F<1> is cut out in order to store the adjustment signals(EAD<1>, EAD<0>)=(1, 0). Consequently, the adjustment signals (EAD<1>,EAD<0>)=(1, 0) are stored in the fuse circuit 41A as the predeterminedsignals (FS<1>, FS<0>)=(1, 0).

FIG. 6 shows a test flow for a case where a predetermined signalsFS<m:0> are stored by executing a trimming test on the internal powersource voltage VII using a tester device as an external control section.A portion surrounded by the parentheses in FIG. 6 indicates processingwithin the semiconductor integrated circuit device.

Test mode is set up in a tester device when the trimming test is started(S1). Consequently, the test signal TS is inverted to low level and atthe same time, the power source voltage VDD is fixed to a predeterminedvoltage value. Further, it is initialized to the adjustment signalsEAD<m:0>=0. With this state, the adjustment signals EAD<m:0> aresupplied successively to the external terminal of the semiconductorintegrated circuit device. The adjustment signals EAD<m:0> are decodedin the semiconductor integrated circuit device so as to output one ofdecoding signals D<n:0> and correspondingly, the internal power sourcevoltage VII is outputted. The outputted internal power source voltageVII is compared for judgment (S2).

As a result of the judgment, the judgment signal JG, which is digitalsignal outputted from the external terminal, is judged (S3). If a lowlevel is maintained (S3: NO), it means that the internal power sourcevoltage VII is not a predetermined value. Therefore, the adjustmentsignals EAD<m:0> are incremented by one and updated (S4). If theincremented adjustment signals EAD<m:0>are not zero which is an initialvalue (S5: NO), a new adjustment signals EAD<m:0> is supplied to theexternal terminal and the processing after S2 is repeated. If theupdated adjustment signals EAD<m:0> return to the initial value 0 (S5:YES), it means that in this semiconductor integrated circuit device, itsinternal power source voltage VII cannot be adjusted to thepredetermined value and then it is determined that this is a defectiveproduct (S6).

If the judgment signal JG turns to a high level as a result of thejudgment (S3: YES), it means that the internal power source voltage VIIis a predetermined value. The value of the adjustment signals EAD<m:0>at this time are acquired as storage data into the fuse circuit (ormemory circuit) 41 (S7). Based on this acquired data, the appropriatefuse elements are cut out (or the adjustment signals EAD<m:0> arefetched in).

FIG. 7 shows a modification of the judgment section. The comparingsection 12B adds resistance elements RC3, RC4 and comparators C2, C3 tothe comparing section 12A (see FIG. 4). The reference voltages of therespective comparators C0-C3 are reference voltages VII0, VII1, VII2,VII3 respectively. The reference voltages VII0-VII3 are obtained bydividing the power source voltage VDD inputted from the externalterminal by resistance elements RC0-RC4. If the voltage value regionbetween the reference voltages VII1 and VII2 is set to a predeterminedvalue, two voltage value regions exist each up and down. Five voltagevalue regions can be identified.

The comparing section 12B identifies in which voltage value region ofthose five regions the internal power source voltage VII exists. Thisidentification is carried out when the comparison signals J<3:0>outputted from the respective comparators C0-C3 are set to “1”successively from the comparison signal J<0> to the comparison signalJ<3>. The encoding section 13B encodes the comparison signals J<3:0> soas to output 3-bit judgment signals JG<2:0>. In an encoding table ofFIG. 7, the judgment signals JG<2:0> are incremented as the comparisonsignals J<3:0> are increased. If the internal power source voltage VIIexists in a predetermined voltage value region, (0, 0, 1, 1) is obtainedas the comparison signals J<3:0>. At this time, (0, 1, 0) are outputtedas the judgment signals JG<2:0>.

The judgment signals JG<2:0> have information about in which voltagevalue region the internal power source voltage VII exists if it existsin other voltage value region than the predetermined voltage valueregion. Thus, the voltage value region of the internal power sourcevoltage VII can be grasped with the judgment signals JG<2:0>, so thattransition of the adjustment signals can be brought near thepredetermined signal more securely and rapidly. Although an example inwhich the judgment signals are 3-bit signals has been described in FIG.7, this signal may be composed of more bits. Consequently, a moreaccurate voltage value region of the internal power source voltage VIIcan be grasped, so that the adjustment signals can be brought near thepredetermined signals more rapidly.

FIG. 8 shows a circuit block diagram of the second embodiment aboutadjustment of the internal power source voltage VII. This circuit has amemory circuit (or fuse circuit) 42 instead of the fuse circuit (ormemory circuit) 41 of the first embodiment (FIG. 3). Additionally, anadjustment signal generating section 71 is incorporated.

The adjustment signal generating section 71 comprises an oscillationcircuit 72 and a counter circuit 73 in which an oscillation signal CLKfrom an oscillation circuit 72 is inputted. Further, the oscillationcircuit 72 and the counter circuit 73 are controlled by the test signalTS inputted to the external terminal T15. The counter circuit 73 countsthe oscillation signal CLK and outputs adjustment signals CAD<m:0> atevery predetermined timing. Here, in order to count the predeterminedtiming, preferably, the oscillation signal CLK is divided or incrementtiming of the counter circuit 73 is subjected to adjustment or the likeappropriately. Consequently, the adjustment signals CAD<m:0> aregenerated in the semiconductor integrated circuit device and therefore,the external terminals T11 (FIG. 3) for use for input of the adjustmentsignals EAD<m:0> are not required. As a result, the quantity of theexternal terminals for adjustment and test for the internal power sourcevoltage VII can be reduced.

Storage of the adjustment signals CAD<m:0> into the memory circuit (orfuse circuit) 42 is controlled within the semiconductor integratedcircuit device. The judgment signal JG is inputted to the memory circuit(or fuse circuit) 42 as a control signal and by writing operation into amemory element based on the judgment signal JG or by cutting of the fuseelement, the adjustment signals CAD<m:0> are fetched in. In this case,the cutting of the fuses is performed by applying an electric stress.The stored signals are supplied as predetermined signals MS<m:0> at thetime of normal operation.

In the meantime, although the judgment signal JG of this case is asignal for internal control, this signal may be outputted from anexternal terminal as digital signal. It is also possible to notify ofcompletion of the adjustment test operation with the judgment signal JGand stop supply of the test signal TS from a tester circuit or the like.

FIG. 9 shows a major component circuit diagram according to a specificexample of the second embodiment. This indicates a case where a 2-bitsignals (m=1) are outputted as adjustment signals CAD <m:0> from thecounter circuit 73A. In the oscillation circuit 72A, the test signal TSinputted from the external terminal T15A is inputted to an inputterminal of the NAND gate as an enable signal. That is, the NAND gate isturned to logical inverting gate by the test signal TS and constitutes aring oscillator together with an inverter gate array connected to theother input terminal.

The counter circuit 73A is a counter circuit in which flip-flop iscascade-connected. The oscillation signal CLK is inputted to a clockterminal (CLK) of the flip-flop of the lowest bit. Then, the adjustmentsignals CAD<1:0> are outputted from each flip-flop. The adjustmentsignals CAD<1:0> are supplied to the multiplexer 51 and at the same timeto the memory circuit 42A.

The memory circuit 42A contains latch sections L0, L1 for each bit ofthe adjustment signals CAD<1:0> as a memory cell. The inputtedadjustment signals CAD<1:0> are connected to the latch sections L0, L1through the transfer gates SC0, SC1. The transfer gates SC0, SC1 areturned ON and controlled depending on a result of logical productoperation between the oscillation signal CLK and the judgment signal JG.More specifically, when it is determined that the internal power sourcevoltage VII is a predetermined value by the adjustment signals CAD<1:0>updated depending on the output of the oscillation signal CLK, a highlevel signal is outputted as the judgment signal JG. The transfer gatesSC0, SC1 are turned ON by a logical product between the high-leveljudgment signal JG and the high level period of the oscillation signalCLK, so that the adjustment signals CAD<1:0> are stored in the latchsections L0, L1 of the memory circuit 42A. The adjustment signalsCAD<1:0> stored in the latch section are supplied to the multiplexer 51as the predetermined signals MS<1:0>.

Because a circuit structure not described in FIG. 9 of the specificexample of the second embodiment is the same as the circuit structure ofthe specific example of the first embodiment (FIG. 4), descriptionthereof is omitted. In this case, inverted signal of the test signal TSis inputted to the multiplexer.

FIG. 10 shows an operation waveform according to a specific example ofthe second embodiment. If the test signal TS is inverted to a highlevel, adjustment test is started. The adjustment signals CAD<1:0>outputted from the counter circuit 73A at every cycle of the oscillationsignal CLK are incremented. Such an operation that the decoding signalsD<0>-D<3> are selected successively depending on the adjustment signalsCAD<1:0> and the internal power source voltage VII is switched so as tooutput the comparison signals J<1:0> and the judgment signal JG is thesame as the specific example of the first embodiment (FIG. 5). Accordingto a specific example of the second embodiment, the adjustment signalsCAD<1:0> are written into the memory circuit 42A based on transition ofthe judgment signal JG to a high level. The written adjustment signalsCAD<1:0> are stored as the predetermined signals MS<1:0>.

According to the specific example of the second embodiment, when thejudgment signal JG turns to a high level during the operation of theadjustment test with the test signal TS kept at a high level, thestorage operation of the adjustment signals CAD<1:0> into the memorycircuit 42A is carried out. FIG. 10 indicates a case where increment ofthe adjustment signals CAD<1:0> are continued after the adjustmentsignals CAD<1:0> are stored into the memory circuit 42A, so that theadjustment test is continued. It is permissible to construct that whenthe storage operation is completed, the test signal TS is transferred toa low level by outputting the judgment signal JG as digital signal fromthe external terminal T12A so as to terminate the adjustment test.

FIG. 11 shows a test flow of a case where trimming test is carried outfor the internal power source voltage VII using an external testerdevice so as to store the predetermined signals MS<m:0>. A portionsurrounded by the parentheses indicates processing within thesemiconductor integrated circuit device.

After the trimming test is started, test mode is set up in the testerdevice (S11). Consequently, the test signal TS is inverted to a highlevel and the power source voltage VDD is fixed to a predeterminedvoltage value. In the semiconductor integrated circuit device whichreceives a high-level test signal TS, the counter circuit is reset sothat the adjustment signals CAD<1:0> are initialized (S12). After that,the adjustment signals CAD<1:0> which are output signals from thecounter circuit is decoded by a decoding signals D<n:0> and then, theinternal power source voltage VII is outputted. Further, comparison withthe predetermined value and judgment is carried out (S13).

If the judgment signal JG which is digital signal outputted from theexternal terminal keeps low level as a result of judgment (S14: NO),unless time-out is reached after time-out of the adjustment test isdetected (S15: NO), comparison and judgment about the internal powersource voltage VII accompanying increment operation of the adjustmentsignals CAD<1:0> within the semiconductor integrated circuit device arecontinued. If the time-out is reached (S15: YES), it is determined thatthis semiconductor integrated circuit device is a defective product(S16).

If the judgment signal JG turns to a high level as a result of thejudgment (S14: YES), the adjustment signals CAD<1:0> are stored asmemory data in the semiconductor integrated circuit device (S17). Thestored data is the predetermined signals MS<1:0>. At this time, thetester device may invert the test signal TS to a low level and terminatethe adjustment test.

A circuit block diagram of the third embodiment for adjustment of theinternal power source voltage VII shown in FIG. 12 indicates a casewhere the adjustment test of the internal power source voltage VII inthe semiconductor integrated circuit device provided with aself-diagnosis test (BIST) circuit 81 is executed as a self-diagnosistest by BIST circuit 81.

Additionally, this block diagram shows a case where the predeterminedsignals MS<m:0> are stored in a nonvolatile memory circuit 43. Becausegenerally, data writing time to the nonvolatile memory circuit 43 islonger than increment period of the adjustment signal BAD<m:0>, thisembodiment includes a latch circuit 44 for temporarily holding theadjustment signals BAD<m:0> to be stored. The adjustment signalsBAD<m:0> are held on the latch circuit 44 and written into thenonvolatile memory circuit 43.

The BIST circuit 81 starts the self-diagnosis test according to the testsignal TS supplied from the external terminal T15. For the adjustmenttest of the internal power source voltage VII, an adjustment test signalTSAD is outputted to the multiplexer 51. At the same time, theadjustment signals BAD<m:0> are transferred and outputted at everypredetermined cycle. The predetermined timing mentioned here refers to atime longer than a time taken until the internal power source voltageVII is updated by the internal power source circuit 31 and theadjustment signals BAD<m:0> are fetched into the latch circuit 44corresponding to the judgment signal JG, this time also including a timefor outputting a judgment result as the judgment signal JG by thejudgment section 11.

The judgment signal JG outputted from the judgment section 11 isinputted to the latch circuit 44 and functions as a latch signal and atthe same time, is inputted to the BIST circuit 81. When the judgmentsignal JG indicating that the internal power source voltage VII turns tobe a predetermined value is inputted, the adjustment signals BAD<m:0> atthis time are fetched into the latch circuit 44 and the program signalPGM is outputted from the BIST circuit 81 into the nonvolatile memorycircuit 43. The adjustment signals BAD<m:0> latched to the latch circuit44 based on the program signal PGM are written into the nonvolatilememory circuit 43. At the same time, transition of the adjustmentsignals BAD<m:0> outputted from the BIST circuit 81 is stopped.

FIG. 13 shows a major component circuit diagram according to a specificexample of the third embodiment. This Figure indicates a case where2-bit signals (m=1) are outputted as the adjustment signals BAD<m:0>from the BIST circuit 81. The adjustment signals BAD<1:0> outputted fromthe BIST circuit 81 are supplied to the multiplexer 51 and at the sametime to the latch circuit 44A.

The latch circuit 44A has the same structure as the memory circuit 42A(FIG. 9). A latch section is provided for each bit of the adjustmentsignals BAD<1:0> and the inputted adjustment signals BAD<1:0> areconnected to the latch section through transfer gate. The transfer gateis turned ON and controlled depending on the judgment signal JG. Thatis, the adjustment signal BAD<1:0> are fetched into the latch sectionbecause the transfer gate is turned ON by the judgment signal JG of ahigh level when it is determined that the internal power source voltageVII is a predetermined value. The adjustment signals BAD<1:0> fetchedinto the latch section is written into a nonvolatile memory cell througha write circuit of the nonvolatile memory cell based on a program signalPGM.

Because the circuit structure not indicated in FIG. 13 of the specificexample of the third embodiment is the same as the circuit structure ofthe specific example (FIG. 4) of the first embodiment, description ofthat section is omitted.

FIG. 14 shows a circuit diagram indicating a first specific example ofthe fourth embodiment of a virtual load section. A PMOS transistor MP2is provided as the virtual load section 24A between the internal powersource voltage VII and the ground voltage. A load signal generatingsection 94A is provided to supply a load signal VG to a gate terminal ofthe PMOS transistor MP2.

In the load signal generating section 94A, the PMOS transistor MP3 andresistance element array are connected in series between the powersource voltage VDD and the ground voltage. A load signal VG is outputtedfrom each connection point of the resistance element array through eachtransfer gate. An inverted signal of the test signal TS is inputted tothe gate terminal of the PMOS transistor MP3 through an inverter gate. Aload setting signals LDS<i:0> are inputted as a digital signal fromexternal terminals T46A. The inputted load setting signals LDS<i:0> aredecoded by a decoding circuit and selects a transfer gate provided ateach connection point of the resistance element array and turns it ON.

The load signal VG is outputted as a predetermined voltage between thepower source voltage VDD and the ground voltage so that the PMOStransistor MP2 is biased. The PMOS transistor MP2 functions as aconstant current source which is turned ON with a predetermined biasstate. Or it can be regarded that a resistance element having apredetermined ON resistance is connected between the internal powersource voltage VII and the ground voltage. A current depending on thisON resistance flows as a load current.

The voltage value of the load signal VG can be set appropriately byexchanging a transfer gate to be turned ON depending on the load settingsignals LDS<i:0>. A current value flowing as the virtual load can be setup appropriately. Further, if the load setting signals LDS<i:0> areexchanged dynamically, a load current of the internal power sourcevoltage VII which changes in actual operation with a time passage can bereproduced falsely.

A second specific example of the fourth embodiment of the virtual loadsection shown in FIG. 15 includes a virtual load section 24B and a loadsignal generating section 94B. In the virtual load section 24B, theinternal power source voltage VII and resistance element are selectivelyconnected through a transfer gate, so that each transfer gate has aresistance element having a different resistance value. Consequently, adifferent load can be connected depending on a transfer gate to beselected and turned ON.

The load signal generating section 94B includes a decoding circuit. Theload setting signals LDS<i:0> to be inputted as digital signal from theexternal terminals T46A are decoded. A transfer gate of the virtual loadsection 24B is selected by decoding signal outputted from the decodingcircuit.

Although the first and second specific examples are indicated in such acondition that the load setting signals LDS<i:0> are inputted from theexternal terminals T46A, this signal may be generated within thesemiconductor integrated circuit device.

The operation waveform shown in FIG. 16 indicates a case where uponadjustment of the internal power source voltage VII, the internal powersource voltage VII becomes a predetermined value with respect toadjacent paring adjustment signals XAD<1:0>(X indicates “E”, “C”, or “B”here). A high-level judgment signal JG is outputted at continuous twocycles. More specifically, when the adjustment signals (XAD<1>,XAD<0>)=(1, 0) are dispatched, a relation VII=VII0 is attained, so thata lower limit value in a voltage value region of the predetermined valueis reached. Further, when the adjustment signals (XAD<1>, XAD<0>)=(1, 1)are dispatched, a relation of VII=VII1 is attained, so that a upperlimit voltage value in a voltage value region of the predetermined valueis reached. Although FIG. 16 indicates a case where the internal powersource voltage VII becomes a predetermined value at continuous twocycles, there is a possibility that the internal power source voltageVII becomes the predetermined value over three or more cycles.

In such a case, if it is so set up that the adjustment signals XAD<1:0>are stored at a first cycle when the judgment signal JG becomes a highlevel, an accurate adjustment signals XAD<1:0> can be stored even whenthe judgment signal JG continues to be a high level over plural cycles.

As described above, according to the semiconductor integrated circuitdevice of this embodiment and the adjustment method of the semiconductorintegrated circuit device, the semiconductor integrated circuit deviceincludes the judgment section 1, 11 and the judgment step is carried outwithin the semiconductor integrated circuit device. For each of theadjustment signals XAD<m:0>(X indicates “E”, “C”, or “B”), the internalpower source voltage VII which is an analog signal outputted from theinternal power source circuit 31, 31A, which is an example of the analogsignal generating section 3, is compared with a predetermined value andjudged. Therefore, the judgment on the internal power source voltage VIIcan be carried out within the semiconductor integrated circuit device.

The internal power source voltage VII does not have to be outputted toan external terminal of the semiconductor integrated circuit device.Thus, the semiconductor integrated circuit device does not requireprovision of an output external terminal of the internal power sourcevoltage VII or wiring for the internal power source voltage VII to theoutput external terminal. Consequently, care to designing on analogwiring is not required, so that designing load of the semiconductorintegrated circuit device can be reduced.

Because the internal power source voltage VII is not outputted from theexternal terminal, any test for analog signal is not required. Only atester device having digital test function needs to be provided for anexternal terminal of digital interface. It is not necessary to providewith any complicated tester device which achieves both digital functionand analog function. Further, test condition exchange between digitalfunction and analog function is not required, thereby reducing anoverhead of the test time which is generated with the test conditionexchange. Consequently, test cost can be reduced.

The reference voltages VII0, VII1, VII0-VII3 for setting thepredetermined value are analog values and obtained by dividing the powersource voltage VDD supplied from the external terminal T13A through theresistance element array of RC0-RC2, RC0-RC4 provided on the comparators12A, 12B. If the power source voltage VDD is set to the predeterminedvoltage value at the time of adjustment test, any analog value forpredetermined value setting does not need to be inputted from anyspecial external terminal.

Further, the predetermined value mentioned here refers to the first andsecond comparison reference values. This value is a predeterminedvoltage value region surrounded by the reference voltages VII0 and VII1(in case of FIG. 4) and the reference voltages VII1 and VII2 (in case ofFIG. 7). Further, it is possible to judge in which region the internalpower source voltage VII exists of voltage value regions partitioned bytwo or more comparison reference values, that is, the reference voltagesVII0 and VII1, VII0 to VII3. Consequently, a difference between theinternal power source voltage VII and the predetermined value can begrasped, so that the adjustment signal can be transferred depending onthe judgment signal JG, JG<2:0> and brought near the predetermined valuerapidly.

Preferably, the judgment section 1, 11 includes plural comparingsections C0, C1 (in case of FIG. 4) or C0-C3 (in case of FIG. 7) forcomparing the internal power source voltage VII with the referencevoltage and encoding sections 13A, 13B in which comparison signals areinputted from plural comparing sections and which identifies in whichvoltage value region the internal power source voltage exists.Consequently, if the judgment signal JG, JG<2:0>, which is an encodingsignal, includes a digital signal having bit number capable ofidentifying a voltage value region, a judgment result can be expressedwith digital signal of minimum bit number. As for the external terminalfor outputting the judgment signal JG, a minimum number of thoseterminals only has to be secured.

Storage of the predetermined signals FS<m:0> into a fuse circuit (ormemory circuit) 41, 41A having fuse elements or memory elements, whichact as a predetermined signal storing section, can be carried outindependently under an external control such as a tester device. After asequence of test based on the tester device is completed, the storageoperation can be carried out.

If the predetermined signal storing section is constituted of memorycircuits (fuse circuits) 42, 42A, 43, 43A, by generating the controlsignal within the semiconductor integrated circuit device based on thejudgment signal JG, the writing of the adjustment signals CAD<m:0>,BAD<m:0> into the memory elements can be executed. Further, by providingthe semiconductor integrated circuit device with a circuit structure forcutting off fuse elements electrically, the fuse elements can be cut outdepending on the adjustment signals CAD<m:0>, BAD<m:0> based on thejudgment signal JG.

The memory elements may be constituted of volatile memory cells used forSRAM, DRAM or the like, like the memory circuit 42A. Further, the memoryelements may be constituted of nonvolatile memory cells electricallyrewritable, provided on a flush memory or the like, like the memorycircuit 43, 43A. Additionally, this function may be achieved by acircuit structure having data holding function such as a register,flip-flop instead of the memory cell.

Further, because virtual load step is executed under provision of thevirtual load sections 24A, 24B, virtual load can be connectedappropriately when the internal power source voltage VII is adjusted.Various kinds of operation conditions in the semiconductor integratedcircuit device such as digital function, other analog function can bereproduced falsely. Consequently, the internal power source voltage VIIcan be adjusted under a load condition near the actual operation.

In the meantime, the present invention is not restricted to theabove-described embodiments, but needless to say, may be improved ormodified in various ways within a scope not departing from the gist ofthe present invention.

For example, although under these embodiments, the internal power sourcecircuit is taken as an example of the analog signal generating sectionand a case where the internal power source voltage VII is adjusted asthe analog signal has been described, the present invention is notrestricted to this example. Additionally, the present invention may beapplied to a case in which a necessity of adjusting other analog valuessuch as bias voltage, bias current exists.

In this case, the virtual load section may be so constructed to connecta current source as a load or to connect an impedance element on a powersource or an analog signal path.

Although as the fourth embodiment, a case where the PMOS transistor or aresistance element is connected as the virtual load section, the presentinvention is not restricted to this example. Needless to say, thevirtual load section may be constituted of the NMOS transistor, ajunction FET, bipolar transistor, diode, capacitor or the like, or otheractive element or passive element or an appropriate combination of theseelements.

According to the semiconductor integrated circuit device and theadjustment method of the same semiconductor integrated circuit device ofthe present invention, when analog signal outputted from the analogsignal generating section such as an internal power source circuitincorporated in the semiconductor integrated circuit device is adjusted,a result of comparison and judgment between the analog signal and apredetermined value does not need be outputted through an externalterminal outside the semiconductor integrated circuit device. Further,the result of comparison and judgment may be converted to digital signaland outputted through the external terminal. That is, an external testerdevice and test method can be simplified so that the adjustment test canbe carried out accurately and rapidly. Further, a pseudo load can beconnected to an analog signal depending on load setting signal andtherefore, the analog signal can be adjusted under a similar loadcondition to the actual operation of the semiconductor integratedcircuit device.

1. A semiconductor integrated circuit device comprising: an analog signal generating section for outputting an analog signal; and a predetermined signal storing section for storing at least one predetermined signal that is supplied to the analog signal generating section and sets the analog signal to a predetermined value, wherein digital signals are used for input/output interface to external terminals, for adjusting the analog signal, the semiconductor integrated circuit device further comprises a judgment section for outputting at least one judgment signal that corresponds to a comparison result of the analog signal corresponding to at least one adjustment signal and the predetermined value generated based on power source voltage, for each adjustment signal supplied to the analog signal generating section in accordance with a test signal, and in case the judgment signal judges that the analog signal has the predetermined value, the adjustment signal corresponding to the as-judged analog signal is stored in the predetermined signal storing section as the predetermined signal.
 2. A semiconductor integrated circuit device according to claim 1 further comprising a signal selecting section that is controlled by the test signal and supplies either the adjustment signal or the predetermined signal to the analog signal generating section.
 3. A semiconductor integrated circuit device according to claim 1, wherein the adjustment or the predetermined signal is digital signals of two or more than two bits and inputted to a decoding section arranged at a preceding stage of the analog signal generating section.
 4. A semiconductor integrated circuit device according to claim 1, wherein the predetermined value is a predetermined analog value region between a first comparison reference value and a second comparison reference value, and the judgment signal judges which analog value region sectioned by two or more comparison reference values including the first and the second comparison reference values the analog signal exists in.
 5. A semiconductor integrated circuit device according to claim 4, wherein the judgment section includes: a plurality of comparing sections for comparing the analog signal with each of the two or more comparison reference values; and an encoding section for outputting encoding signals in a manner of receiving output signals from the plurality of comparing sections and discriminating the analog value region where the analog signal exists.
 6. A semiconductor integrated circuit device according to claim 4, wherein the two or more comparison reference values are obtained by lowering/dividing power source voltage.
 7. A semiconductor integrated circuit device according to claim 1, wherein the analog signal generating section is an internal power source voltage generating section and outputs internal power source voltage as the analog signal.
 8. A semiconductor integrated circuit device according to claim 1, wherein the predetermined signal storing section includes memory elements or fuse elements, and the predetermined signal storing section is controlled inside the semiconductor integrated circuit device based on the judgment signal for data-write on the memory elements or cutting out the fuse elements.
 9. A semiconductor integrated circuit device according to claim 1, wherein the judgment signal is a digital signal and outputted from the external terminal.
 10. A semiconductor integrated circuit device according to claim 1, wherein the predetermined signal storing section includes fuse elements or memory elements, and based on external control to the judgment signal outputted, data-write on the memory elements or cutting out of the fuse elements is conducted.
 11. A semiconductor integrated circuit device according to claim 1 further comprising an adjustment signal generating section for outputting the adjustment signal in order under activation control by the test signal.
 12. A semiconductor integrated circuit device according to claim 11, wherein the adjustment signal generating section includes an oscillation section for outputting an oscillation signal having predetermined frequency, and counter section for counting the oscillation signal, transitioning and outputting the adjustment signal with constant cycle based on the predetermined frequency.
 13. A semiconductor integrated circuit device according to claim 1 further comprising a self-diagnosis test circuit for executing predetermined tests for the predetermined internal circuits inside the semiconductor integrated circuit device, wherein adjustment test of the analog signal is executed as one of tests by the self-diagnosis test circuits.
 14. A semiconductor integrated circuit device according to claim 13, wherein the test signal, the adjustment signal, and the judgment signal are inputted to/outputted from the self-diagnosis test circuit.
 15. An adjustment method of a semiconductor integrated circuit device that generates an analog signal having a predetermined value based on at least one predetermined signal stored and uses digital signals for input/output interface to external terminals, for adjusting the analog signal, the adjustment method comprising the steps of: a signal generating step for generating the analog signal that corresponds to at least one adjustment signal; a judgment step for judging a comparison result of the analog signal generated and the predetermined value generated based on power source voltage, the judgment step being executed inside the semiconductor integrated circuit device; and a storing step for storing the adjustment signal as the predetermined signal in case the analog signal is judged as having the predetermined value through the judgment step.
 16. An adjustment method of a semiconductor integrated circuit device according to claim 15, wherein the adjustment signal makes stepwise transition and the signal generating step and the judgment step are repeated for each adjustment signal.
 17. An adjustment method of a semiconductor integrated circuit device according to claim 15, wherein the storing step is executed inside the semiconductor integrated circuit device.
 18. An adjustment method of a semiconductor integrated circuit device according to claim 15, wherein judgment of the comparison result is outputted from at least one of the external terminals in a form of at least one digital signal.
 19. An adjustment method of a semiconductor integrated circuit device according to claim 18, wherein the storing step is controlled outside the semiconductor integrated circuit device.
 20. An adjustment method of a semiconductor integrated circuit device according to claim 19, wherein the storing step includes: a signal obtaining step for obtaining the adjustment signal as the predetermined signal in case the analog signal is judged as having the predetermined value; and a write step for writing the obtained predetermined signal in a predetermined signal storing section. 